[PATCH 02/11] procfs: Don't cache a pid in the root inode.

From: Eric W. Biederman
Date: Fri Nov 16 2012 - 11:38:20 EST


From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

Now that we have s_fs_info pointing to our pid namespace
the original reason for the proc root inode having a struct
pid is gone.

Caching a pid in the root inode has led to some complicated
code. Now that we don't need the struct pid, just remove it.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
fs/proc/base.c | 11 +----------
fs/proc/root.c | 8 --------
2 files changed, 1 insertions(+), 18 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index cbe454e..6177fc2 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2714,19 +2714,12 @@ static int fake_filldir(void *buf, const char *name, int namelen,
/* for the /proc/ directory itself, after non-process stuff has been done */
int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
- unsigned int nr;
- struct task_struct *reaper;
struct tgid_iter iter;
struct pid_namespace *ns;
filldir_t __filldir;

if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
- goto out_no_task;
- nr = filp->f_pos - FIRST_PROCESS_ENTRY;
-
- reaper = get_proc_task(filp->f_path.dentry->d_inode);
- if (!reaper)
- goto out_no_task;
+ goto out;

ns = filp->f_dentry->d_sb->s_fs_info;
iter.task = NULL;
@@ -2747,8 +2740,6 @@ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
}
filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
out:
- put_task_struct(reaper);
-out_no_task:
return 0;
}

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 5da9849..13ef624 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -100,7 +100,6 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
int err;
struct super_block *sb;
struct pid_namespace *ns;
- struct proc_inode *ei;
char *options;

if (flags & MS_KERNMOUNT) {
@@ -130,13 +129,6 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
sb->s_flags |= MS_ACTIVE;
}

- ei = PROC_I(sb->s_root->d_inode);
- if (!ei->pid) {
- rcu_read_lock();
- ei->pid = get_pid(find_pid_ns(1, ns));
- rcu_read_unlock();
- }
-
return dget(sb->s_root);
}

--
1.7.5.4

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